MIQuant – Semi-Automation of Infarct Size Assessment in Models of Cardiac Ischemic Injury

BACKGROUND: The cardiac regenerative potential of newly developed therapies is traditionally evaluated in rodent models of surgically induced myocardial ischemia. A generally accepted key parameter for determining the success of the applied therapy is the infarct size. Although regarded as a gold standard method for infarct size estimation in heart ischemia, histological planimetry is time-consuming and highly variable amongst studies. The purpose of this work is to contribute towards the standardization and simplification of infarct size assessment by providing free access to a novel semi-automated software tool. The acronym MIQuant was attributed to this application. METHODOLOGY/PRINCIPAL FINDINGS: Mice were subject to permanent coronary artery ligation and the size of chronic infarcts was estimated by area and midline-length methods using manual planimetry and with MIQuant. Repeatability and reproducibility of MIQuant scores were verified. The validation showed high correlation (r(midline length) = 0.981; r(area) = 0.970 ) and agreement (Bland-Altman analysis), free from bias for midline length and negligible bias of 1.21% to 3.72% for area quantification. Further analysis demonstrated that MIQuant reduced by 4.5-fold the time spent on the analysis and, importantly, MIQuant effectiveness is independent of user proficiency. The results indicate that MIQuant can be regarded as a better alternative to manual measurement. CONCLUSIONS: We conclude that MIQuant is a reliable and an easy-to-use software for infarct size quantification. The widespread use of MIQuant will contribute towards the standardization of infarct size assessment across studies and, therefore, to the systematization of the evaluation of cardiac regenerative potential of emerging therapies

The interstitium in cardiac repair: role of the immune-stromal cell interplay

Cardiac regeneration, that is, restoration of the original structure and function in a damaged heart, differs from tissue repair, in which collagen deposition and scar formation often lead to functional impairment. In both scenarios, the early-onset inflammatory response is essential to clear damaged cardiac cells and initiate organ repair, but the quality and extent of the immune response vary. Immune cells embedded in the damaged heart tissue sense and modulate inflammation through a dynamic interplay with stromal cells in the cardiac interstitium, which either leads to recapitulation of cardiac morphology by rebuilding functional scaffolds to support muscle regrowth in regenerative organisms or fails to resolve the inflammatory response and produces fibrotic scar tissue in adult mammals. Current investigation into the mechanistic basis of homeostasis and restoration of cardiac function has increasingly shifted focus away from stem cell-mediated cardiac repair towards a dynamic interplay of cells composing the less-studied interstitial compartment of the heart, offering unexpected insights into the immunoregulatory functions of cardiac interstitial components and the complex network of cell interactions that must be considered for clinical intervention in heart diseases

Frailty identification and management among Brazilian healthcare professionals: a survey

Background National and international guidelines on frailty assessment and management recommend frailty screening in older people. This study aimed to determine how Brazilian healthcare professionals (HCPs) identify and manage frailty in practice. Methods An anonymous online survey on the assessment and management of frailty was circulated virtually through HCPs across Brazil. Results Most of the respondants used non-specific criteria such as gait speed (45%), handgrip strength (37.6%), and comprehensive geriatric assessment (33.2%). The use of frailty-specific criteria was lower than 50%. The most frequently used criteria were the Frailty Index (19.1%), Frailty Phenotype (13.2%), and FRAIL (12.5%). Only 43.5% felt confident, and 40% had a plan to manage frailty. In the multivariate-adjusted models, training was the most crucial factor associated with assessing frailty, confidence, and having a management plan (p < 0.001 for all). Those with fewer years of experience were more likely to evaluate frailty (p = 0.009). Being a doctor increased the chance of using a specific tool; the opposite was true for dietitians (p = 0.03). Those who assisted more older people had a higher likelihood of having a plan (p = 0.011). Conclusion Frailty assessment was heterogeneous among healthcare professions groups, predominantly using non-specific criteria. Training contributed to frailty assessment, use of specific criteria, confidence, and having a management plan. This data informs the need for standardized screening criteria and management plans for frailty, in association with increasing training at the national level for all the HCPs who assist older people